Localization and Activity of iNOS in Normal Human Lung Tissue and Lung Cancer Tissue

Inducible nitric oxide synthase (iNOS) is one of three enzymes generating nitric oxide (NO) from the amino acid L-arginine. iNOS-derived NO plays an important role in several physiological and pathophysiological conditions. NO is a free radical which produces many reactive intermediates that account for its bioactivity. In the human lung, the alveolar macrophage is an important producer of cytokines and this production may be modified by NO. Moreover, high concentrations of NO have been shown to increase nuclear factor KB (NF-kB) activation. Recent investigations of NO expression in tumor tissue indicated that, at least for certain tumors, NO may mediate one or more roles during the growth of human cancer. We have studied iNOS in two tissue groups: normal human lung tissue and human lung cancer tissue. We localized iNOS in these tissues by immunohistochemistry and tested the mRNA expression by RT-PCR, the protein level by Western blot, and the protein activity by radiometric analysis. The results demonstrate different expression, localization and activity of iNOS in normal versus tumor tissue. This is suggestive of a role for NO production from iNOS in human lung cancer because high concentrations of this short molecule may transform to highly reactive compounds such as peroxynitrite (ONOO-); moreover, through the upregulator NF-kB, they can induce a chronic inflammatory state representing an elevated risk for cell transformation to cancer.

Intestinal schistosomiasis manifesting as colonic intussusception arising from a mucocele of the appendix: report of a case

We report a case of intestinal schistosomiasis manifesting as colonic intussusception resulting from a mucocele of the appendix, caused by the obstruction of appendiceal outflow by schistosome egg-induced fibrosis. An 81-year-old woman from China presented with a tender right iliac fossa mass and computed tomography (CT) showed intussusception in the ascending colon. Exploratory laparotomy confirmed an appendiceal mass causing intussusception of the cecum into the ascending colon, with the appendix as the lead point, and lymphnode enlargement. We performed a right hemicolectomy for the appendiceal tumor. However, histologic examination revealed schistosoma eggs within the mucosa, submucosa, muscularis propria, and subserosal fat of the appendix, cecum, and ascending colon, and lymph nodes. The absence of dysplasia in the appendiceal mucosa indicated that the mucocele had developed from fibrosis induced by schistosome eggs obstructing the luminal outflow of mucin. Postoperatively, the patient was given praziquantel and recovered well.

In vitro stem cell cultures from human dental pulp and periodontal ligament: new prospects in dentistry

In spite of the vast knowledge of tooth development and of the various kinds of specialized bone/tooth-associated cells, the characteristics and properties of their precursor cell populations present in the postnatal organism are little known, as is their possible therapeutic use. Taken together dental pulp stem cells (DPSCs) and periodontal ligament stem cells (PDLSCs) possess stem-cell-like qualities, including self-renewal capability and multi-lineage differentiation. Regenerative medicine is based on stem cells, signals and scaffolds. Transplantation of those cells, which can be obtained from an easily accessible tissue resource and expanded in vitro, holds promise as a therapeutic approach for reconstruction of tissues and bone in vivo.